1. Field of the Invention
The present invention relates to the absorption of kinetic energy of fluids produced from an oil well into one end of a horizontal separator vessel to distribute the fluids in a plane transverse the vessel axis. More specifically, the invention relates to reducing the kinetic energy of, and distributing, the oil well fluids produced into one end of a horizontal separator vessel so the gaseous portion of the fluids will move uniformly down the flow path provided in the upper part of the vessel to the gaseous outlet of the vessel with efficient separation of liquids from the gaseous portion of the fluids.
2. Description of the Prior Art
Separation of fluids produced from oil wells is now an ancient and honorable art in the oil fields. Basically, the gaseous portion of oil well production must be separated from liquids and the liquids must be separated into their water and oil phases. The principles applied to bring about this separation have the deceptive appearance of simplicity. However, the massive quantity of fluids involved in well production give rise to the tremendous economic importance in the application of these principles. Low temperature separation made its debut on the production scene many years ago. The high pressure in the order of thousands of pounds per square inch at which some production reached the surface has spelled out a source of energy often shamelessly wasted but sometimes partially exploited to advantage. Reducing this pressure with proper regulation results in at least the cooling effect of adiabatic expansion.
The formation of hydrates in predominately gaseous well streams which have been reduced in pressure has facilitated the removal of liquifiable water and hydrocarbon from more volatile portions of their well streams. Under this principle, a low temperature separator had its birth in the oil fields.
A degree of controversy has always revolved around the choice between a horizontally extended vessel and a vertically extended vessel. In general, the need for a bath of relatively warm liquid into which the hydrates could be gravitated has favored the horizontal form. No manufacturer of oil field equipment has even closely rivaled the exploits of the National Tank Company of Tulsa, Okla., in providing an acceptable form of low temperature separator to the oil field producer.
With the general decline of native high pressure in the oil fields, the low temperature separator may be said to be entering upon its autumn years. However, future techniques of exploration may put the lie to these discouraging opinions. Whatever future there is to the low temperature separator, it will continue to be written in the engineering potential of Combustion Engineering, Inc. of Windsor, Conn., which purchased the assets of National Tank Company some years ago.
Many and varied are the problems of construction and operation of the low temperature separator solved by the engineers of the old National Tank Company. The outline of these problems, and their solutions, may be traced, to a large extent, through the patent activity of the National Tank Company inventors. These issued patents form the core of the patent literature in this art. The following list gives a rather comprehensive view of this literature which has been reviewed for its disclosure relating to the energy absorption structure within the separator for the fluids drastically reduced in pressure from their wells.
______________________________________ NUMBER FILING DATE INVENTOR ______________________________________ 2,711,826 AUGUST 30, 1951 C. E. DEYOUNG ET AL 2,747,002 OCTOBER 24, 1952 J. P. WALKER ET AL 2,728,406 SEPTEMBER 25, 1953 J. L. MAHER 2,738,026 NOVEMBER 2, 1953 C. O. GLASGOW ET AL 2,758,665 DECEMBER 20, 1954 A. W. FRANCIS, JR. 2,809,713 JULY 9, 1956 R. W. COGGINS 2,873,814 APRIL 22, 1957 J. L. MAHER RE, 25,759 JULY 25, 1958 J. P. WALKER ET AL ______________________________________
A study of these patent disclosures demonstrates that little attention has been given the spinner into which the incoming fluids have been directed. Essentially, the spinner is no more than a ring, the incoming fluids being flowed tangentially around the internal surface of the ring. In broad principle, this form of structure for diversion of flow streams has long been a feature of the separator art, not limited to the low temperature separator. The only structure mounted on the spinner has been some form of heating device. Localized heating of the spinner is practiced to avoid build-up of hydrates formed by the pressure reduction of the well stream impinging upon the inner surface of the spinner.
Discharge of the diverted fluids of the spinner structure has simply been the result of gravity pulling the fluids downward toward the lower liquid bath carried in the lower portion of the horizontal separator vessel. No concern has been given in the past to the distribution of these fluids after their pressure has been reduced and they have been diverted by the spinner. It has always been simply expected that the hydrates formed would find their way into the relatively warm liquid bath below and the separated gaseous portion would exit the vessel from an upper outlet provided downstream from the vessel inlet. The problems of providing proper valving to reduce pressure of the fluids, heating the liquid bath, isolating the upstream cool portion of the vessel from the downstream liquid discharge compartments and arrangements for separating the oil from the water have challenged the creative ingenuity of the engineers charged with the responsibilities of providing a workable product to the industry. Some concern has been given to the amount of liquid carryover actually appearing at the gas outlet of the vessel. Lately, this concern has resulted in measurements of this carryover which have rung the alarm bell in the Tulsa office of the C-E Natco Division of Combustion Engineering, Inc. The first observations brought to light the problem that the fluid stream emerging from the spinners was all too often directed down into the liquid bath below to re-entrain liquids in the gaseous portions which reach the gas outlet of the low temperature separator. Further, the distribution of the gaseous fluids was apparently so inconsistent across the upper portion of the horizontal vessel that the hydrating liquids reached the gas outlet of the vessel before they could be disengaged into the liquid bath in the lower portion of the vessel. Order must be brought out of this chaos to reduce the carryover of liquid at the gaseous outlet of the vessel.